Method for removing incrustations



new 1965 c. H. HEIST METHOD FOR REMOVING INCRUSTATIONS Filed Sept. 25,1965 INVENTOR. F/m'WZ'ez-s fl. ]'[e is? BY W fl/ ATTORNEY.-

United States Patent M 3,226,258 METHOD FOR REMOVING INCRUSTATHONSCharles H. Heist, East Aurora, N.Y., assiguor to C. H. Heist OhioCorporation, Buffalo, N.Y., a corporation of New York Filed Sept. 25,1963, Ser. No. 311,414 1 Claim. (Cl. 134-8) The present inventionrelates to an improved method for removing incrusted foreign matter fromthe insides of tubes and the like.

In heat exchangers, boilers, and tubes which are utilized to conductchemicals in industrial processes there is a depositing of incrustationson the insides of said tubes which initially impede the flow of fluidsthrough said tubes and eventually block off the tubes completely so thatthe processes which utilize said tubes operate at greatly reducedefliciencies with an obvious attendant economic loss. In the past,various methods have been utilized for removing the above-mentionedincrustations. Included among these methods was the use of a rotarydrill mounted at the end of a spindle. However, this method had theprimary shortcoming of being very costly in that the drill became dullwith short periods of use and therefore required frequent replacementand sharpening. In the foregoing prior art method it was common to use afluid for flushing the debris which was drilled out of the tube. Howeverthis flushing in no way acted on the incrustation to aid in thedislodging thereof from its position on the inside of the tube. Othermethods were also utilized which relied solely on the projecting of highpressure fluids against deposits on the insides of tubes to dislodgeforeign matter therefrom. However these methods were deficient in that,while the fluids were under high pressure, the pressure was frequentlygreatly dissipated and reduced by the time that the fluid impinged onthe deposits thereby resulting in an unsatisfactory cleaning action.Furthermore, the use of high pressure fluid by itself could not do aneffective cleaning job. It is with the overcoming of the foregoingshortcomings of the prior art that the present invention is concerned.

It is accordingly the primary object of the present invention to providean improved method for removing extremely hard incrustations from theinsides of tubes and the like which is highly efficient in that theincrustations are removed rapidly and completely without leaving traceswhich would serve as focal points for subsequent build-up ofincrustations.

Another object of the present invention is to provide an improved methodfor removing incrustations from the insides of tubes and the like whichis highly economical in that the apparatus utilized to remove saidincrustations does not wear out rapidly and does not require frequentreplacement. Other objects and attendant advantages of the presentinvention will readily be perceived hereafter.

The improved method of removing hardened incrusted foreign matter fromthe insides of tubes or the like comprises the steps of effecting adrilling action within said tube to disengage said foreign mattertherefrom and simultaneously projecting high pressure fluid radiallyand/or axially of the direction of drilling in the area of saiddrilling, said fluid being under sufiicient pressure, when it impingeson said incrustations, to provide an eroding action whereby said erodingaction cooperates with and complements said drilling to facilitate theremoval of said foreign matter by (l) eroding a portion of the foreignmatter which is subsequently removed by said drilling and by (2)removing traces of foreign matter which remain on the inside of saidtube after said drill- 3,226,258 Patented Dec. 28, 1965 ing and by (3)acting in concert with said drilling, to thereby rapidly and completelyremove said incrustations of foreign matter from the inside of saidtube. The drill not only performs its function as a drill but also actsas a guide to center the high pressure fluid which is discharged ontothe inside of the tube to thereby cause it to act most effectively.

The apparatus of the present invention for removing incrusted foreigndeposits from the insides of tubes includes a drill, a motor, a hollowspindle connecting said drill and said motor to thereby transmit. motionfrom said motor to said drill, a source of pressurized fluid underpressure suflicient to erode said foreign matter when said fluid isimpinged thereon, conduit means for conducting said pressurized fluidfrom said source to said hollow spindle, and apertures in said drill forprojecting said pressurized fluid in the area in which said drill isrotated to thereby remove said foreign matter by a combined drilling anderoding action. The present invention will be more fully understood whenthe following portions of the specification are read in conjunction withthe accompanying drawings wherein:

FIG. 1 is a schematic view of the improved apparatus which is utilizedfor practicing the improved method of the present invention; and

FIG. 2 is a cross sectional view of a portion of the apparatus of thepresent invention.

In FIG. 1 an air motor 10 is shown having a housing 11 including acompressed air inlet 12 and a compressed air outlet 13. A pair ofhandles 14 (one on each opposite side of housing 11) are provided forgrasping by the motor operator to guide the direction of movement ofsaid motor. An eye hook 15 is suitably secured to housing 11 for hangingmotor 10 from a support because of its weight. A grip 16 is pivotallymounted on housing 11 and includes an extension 17 connected to grip 16by O-portion 18, extension 17 being in engagement with the stem of avalve (not shown) which controls the amount of compressed air which ispermitted to enter housing 11 from conduit 12. In this manner the speedof motor 10 is controlled. Motor 10 may be in all respects identical tomotor number CC-325-1 which is manufactured by the AiretoolManufacturing Company of Springfield, Ohio, except for certainmodifications which will be described hereafter in conjunction with FIG.2.

A pump 19 is provided for receiving water which enters this pump fromconduit 20 and leaves said pump through conduit 21. Pump 19 is capableof increasing the water pressure to a magnitude of approximately 4,000pounds per square inch. However, in the instant process which will bedescribed in greater detail hereafter, the pressure need only be of themagnitude of approximately 3,000 pounds per square inch. The end ofconduit 21 remote from pump 19 is in communication with valve 22, whichin turn is mounted on nipple 23 extending from portion 24 of housing 11.More specifically, nipple 23 fits into bushing 25 which is threaded intohousing portion 24 and set screw 26 retains said bushing 25 in position.A second bushing 27 threads into the internal portion of bushing 25, asis clearly shown in FIG. 2, and a heavy duty gasket or seal 28 is wedgedbetween wall 29 of bushing 25 and end wall 30 of bushing 27. Gasket orseal 28 is of sufliciently sturdy construction and sealing power toprevent leakage of the fluids under a pressure of approximately 3,000pounds per square inch. Rotatably mounted within bushing 27 is the rightend of hollow spindle 31, the left end thereof being splined orotherwise keyed to gear 32 which is in mesh with pinion 33 driven byshaft 34 of the air driven rotor (not shown) within motor 10. A pair ofthrust bearings 35 are suitably mounted within housing portion 36 tolimit endwise movement of spindle 31.

Thus, because of seal 28 in conjunction with bushings 25 and 27, thehigh pressure fluid in conduit 21 is conducted into hollow rotatingspindle 31 without leakage. This fluid is transmitted by hollow spindle31 into hollow spindle 37 which is threaded onto hollow spindle 31 at38. The end of hollow spindle 37 remote from connection 38 mounts adrill bit 39 having a pair of apertures 40 on opposite sides thereofwhich project the high pressure fluid from spindle 37 axially forwardlyof the direction of rotation of drill 39. Furthermore a pair ofapertures 41 are located on opposite sides of drill 39 for projectinghigh pressure fluid radially of the direction of movement of the drill39 as it moves through tube 42 forming a part of heat exchanger 43 orthe like. Apertures 40 and 41 in essence project jets of fluid whichprovide the desired eroding action.

It will readily be seen that the high pressure fluid being discharged ata magnitude of approximately 3,000 pounds per square inch is caused toimpinge on the incrustations within the tube in the vicinity of the areain which drilling occurs. The pressurized fluid, when it impinges on theincrustations, has suificient force to actually erode saidincrustations. Thus there is a three-fold action which is effected bythe combined drilling and eroding, namely, (1) the high pressure fluidwhich is projected forwardly of the drill tears away or erodes a part ofthe incrustations 40 lying ahead of the drill, (2) the high pressurefluid which is projected in the vicinity in which the drilling actuallyoccurs aids the drilling to thereby effect removal of the incrustations41 within the tube by combined eroding and drilling action, therebyprolonging drill life by minimizing the wear to which the drill issubjected, and (3) the high pressure fluid being projected fromapertures 41 impinge on the sides of the conduit When these sides are nolonger in engagement with the drill to thereby remove any rifling 42' ofincrustations which may remain within the tube to thereby remove anyirregular surfaces which may act as focal points for the accumulation ofsubsequent incrustations. It is also to be especially noted that thedrill acts as a guide to cause the high pressure fluids which areprojected from apertures 40 and 41 to follow a predetermined path bybeing projected in a predetermined direction. Furthermore the drill 39regulates the spacing of the apertures from the walls of the tube tothereby insure that the jets of fluid are projected with the desiredforce onto the walls of the tube.

It will also be appreciated that when the drill 39 is removed from tube42 it travels from left to right, whereas when it was inserted ittraveled from right to left in FIG. 1. By maintaining the discharge ofhigh pressure fluid from apertures 40 and 41 during said Withdrawalwhile drill 39 is rotating, the finishing touches are provided to thecleaning operation to thereby completely clean said tube of anyincrustations which may have remained after the three-faceted actiondescribed in detail above.

It is to be noted that drill 39 was described in FIG. 1 as havingapertures which project the high pressure fluid both forwardly andradially of the direction of movement of the drill. However it will bereadily appreciated that certain modifications may be made within thescope of the present invention, namely, that a drill bit having onlyradial apertures may be utilized or having only forwardly projectingapertures may be utilized and the number and location of said aperturesmay be varied to meet the exigencies of any particular type of cleaningoperation, it being appreciated that different types of incrustationsrequire different types of treatment.

It is to be especially noted that the use of high pressure fluids toprovide an eroding action causes the instant method to differ greatlyfrom those prior art methods which utilized fluids to provide only aflushing action which merely carried the dislodged debris away from thearea of drilling. The use of high pressure fluids of the magnitudedescribed herein inherently performs the flushing function of the priorart, in addition to the eroding function which accompanies the drilling,as described above.

It is also to be noted that while the fluid which is utilized, has beendescribed above as water, other suitable fluids may also be used, or thewater may contain abrasive material to provide an improved erodingaction.

While preferred embodiments of the present invention have beendisclosed, it will readily be appreciated that the present invention isnot limited thereto, but may be otherwise embodied within the scope ofthe following claim.

I claim:

A method of removing extremely hard incrusted foreign matter from theinside surface of a tube comprising the steps of effecting a drillingaction through said tube to disengage said foreign matter therefrom andsimultaneously projecting fluid axially of the direction of saiddrilling in the area of said drilling, said fluid being under a pressureof approximately 3,000 pounds per square inch to thereby effect anerosion of said foreign matter and provide an action wherein saideroding cooperates with and complements said drilling to facilitate theremoval of said foreign matter by acting simultaneously on the sameportions of said extremely hard incrusted foreign matter in concert withsaid drilling, by loosening foreign matter which is subsequently removedby said drilling and by removing foreign matter which remains on theinside of said tube after said drilling.

References Cited by the Examiner UNITED STATES PATENTS 1,161,122 11/1915Froussard 15104.1 1,218,765 3/1917 Hauer l5-l04.1 1,628,070 5/1927Sladden 15-104.12 1,803,425 5/ 1931 Cunningham.

1,932,068 10/1933 Englebright et a1. 15104.1 X 2,218,130 10/1940 Court15--104.12 2,313,042 3/1943 Bay 15104.1 2,336,293 12/1943 Pletcher15104.12 2,423,257 7/1947 Schott et al 15--104.1 2,710,980 6/1955Pletcher 15104.12 2,932,836 4/1960 Pletcher 15104.12

CHARLES A. WILLMUTH, Primary Examiner.

